Rinnai RU98e User manual

Direct Vent Tankless Water Heater
Installaon and Operaon Manual



 
 
 
 



WARNING

This manual provides informaon on the installaon, operaon, and maintenance of the water heater. For proper
operaon and , it is important to follow the instrucons and adhere to the safety precauons.
A licensed professional must install the water heater according to the exact instrucons on pages 4-32.
The consumer must read the enre manual to properly operate the water heater and to have regular maintenance
performed.

FOR INDOOR APPLICATIONS ONLY
RU80i.................... --
RU98i.................... --
FOR OUTDOOR APPLICATIONS ONLY
RU80e................... --
RU98e................... --

2KB Series Manual

This is the safety alert symbol. This symbol alerts you to potenal hazards that can kill or hurt you
and others.
Indicates an imminently hazardous situaon which, if not avoided, will result in death or
serious injury.
Indicates a potenally hazardous situaon which, if not avoided, could result in death or
serious injury.
Indicates a potenally hazardous situaon which, if not avoided, could result in minor or
moderate injury. It may also be used to alert against unsafe pracces.
DANGER
CAUTION
WARNING
Table of Contents..................................................... 2
Safety Behaviors and Pracces for the
Consumer and Installer ............................................ 3

 ............................. 
Prepare for Installaon......................................5
Determine Installaon Locaon ........................6
Checklist to Determine Installaon Locaon...12
Mount to Wall..................................................12
Remove the Front Panel ..................................12
Installaon of Venng (indoor models only) ...13
Twin Pipe PVC/CPVC Vent Installaon........17-36
Condensate (indoor models only)....................37
Checklist for Venng and Condensate
(indoor models only)........................................37
Installaon of Plumbing...................................38
Checklist for Plumbing .....................................41
Installaon of Gas Supply ................................41
Connect Electricity ...........................................43
Adjust for High Altude ...................................43
Adjust for Vent Length (indoor models only) ..43
Checklist for Gas and Electricity.......................43
Installaon of Temperature Controller............44
Final Checklist...................................................46
Technical Data ........................................................47
Specicaons ...................................................47
Dimensions.......................................................48
Pressure Drop and Water Flow Curves............49
Ladder Diagram................................................50
Recirculaon Mode..........................................51
 .......................................
Consumer Operaon Guidelines for the
Safe Operaon of your Water Heater ....................54
How to Use the Temperature Controller ...............55
How to Set the Temperature..................................56
Diagnosc Codes ....................................................58
Required Maintenance...........................................61
Flushing the Heat Exchanger............................63
Manual Draining of the Water Heater.............64
State Regulaons....................................................65
Replacement Parts .................................................66
Consumer Warranty ...............................................68
French Version........................................................70


NOTICE: Rinnai somemes shares customer contact informaon with businesses that we believe provide
products or services that may be useful to you. By providing this informaon, you agree that we can
share your contact informaon for this purpose. If you prefer not to have your informaon shared with
these businesses, please contact customer service and ask not to have your informaon shared. We
will however, connue to contact you with informaon relevant to the product(s) you registered and/
or you account with us.
If you have any quesons or feel that the manual is incomplete contact Rinnai at 1-800-621-9419.

KB Series Manual 3
CAUTION
 BURN HAZARD. Hot exhaust and vent may cause
serious burns. Keep away from the water heater
unit. Keep small children and animals away from
unit.
 Hot water outlet pipes leaving the unit can be hot
to touch. In residenal applicaons, insulaon
must be used for hot water pipes below 36” due to
burn risk to children.
California law requires this noce to be provided:
lists chemical substances known to the state to cause cancer, birth defects, death,
serious illness or other reproducve harm. This product may contain such substances, be their origin from fuel
combuson (gas, oil) or components of the product itself.

 Before operang, smell all around the appliance
area for gas. Be sure to smell next to the oor
because some gas is heavier than air and will sele
on the oor.
 Keep the area around the appliance clear and free
from combusble materials, gasoline, and other
ammable vapors and liquids.
 Combusble construcon refers to adjacent walls
and ceiling and should not be confused with
combusble or ammable products and materials.
Combusble and/or ammable products and
materials should never be stored in the vicinity of
this or any gas appliance.
 Always check the water temperature before
entering a shower or bath.
 To protect yourself from harm, before performing
maintenance:
 Turn o the electrical power supply by
unplugging the power cord or by turning o the
electricity at the circuit breaker. (The
temperature controller does not control the
electrical power.)
 Turn o the gas at the manual gas valve, usually
located immediately below the water heater.
 Turn o the incoming water supply. This can be
done at the isolaon valve immediately below
the water heater or by turning o the water
supply to the building.
WARNING
 Use only your hand to push in or turn the gas
control knob. Never use tools. If the knob will not
push in or turn by hand, do not try to repair it; call a
licensed professional. Force or aempted repair
may result in a re or explosion.
 Do not use this appliance if any part has been under
water. Immediately call a licensed professional to
inspect the appliance and to replace any part of the
control system and any gas control which has been
under water.
 Do not use substute materials. Use only parts
cered with the appliance.
 Should overheang occur or the gas supply fail to
shut o, turn o the manual gas control valve to the
appliance.
 Do not adjust the DIP switch unless specically
instructed to do so.
 Do not use an extension cord or an adapter plug
with this appliance.
 Any alteraon to the appliance or its controls can be
dangerous and will void the warranty.

4KB Series Manual
A licensed professional must install the appliance,
inspect it, and leak test it before use. The warranty
will be voided due to improper installaon.
The installer should have skills such as:
 gas sizing
 connecng gas lines, water lines, valves,
electricity,
 knowledge of applicable naonal, state, and
local codes.
 installing venng through a wall or roof
If you lack these skills contact a licensed professional.


Prepare for Installaon ......................................5
Determine Installaon Locaon.........................6
Checklist to Determine Installaon Locaon...11
Mount to Wall..................................................11
Remove the Front Panel ..................................11
Installaon of Venng (indoor models only) ...12
Condensate (indoor models only)....................15
Checklist for Venng and Condensate
(indoor models only)........................................15
Installaon of Plumbing ...................................16
Checklist for Plumbing .....................................19
Installaon of Gas Supply.................................19
Connect Electricity ...........................................21
Adjust for High Altude ...................................21
Adjust for Vent Length (indoor models only) ..21
Checklist for Gas and Electricity.......................21
Installaon of Temperature Controller............22
Final Checklist...................................................24


 Do not install the RU80i or the RU98i outdoors.
 Do not install the RU80e or the RU98e indoors.
 Do not install the appliance in an area where water
leakage of the unit or connecons will result in
damage to the area adjacent to the appliance or to
lower oors of the structure. When such locaons
cannot be avoided, it is recommended that a
suitable drain pan, adequately drained, be installed
under the appliance. The pan must not restrict
combuson air ow.
 Do not obstruct the ow of combuson and
venlaon air. Combuson air shall not be
supplied from occupied spaces.
 Do not use this appliance in an applicaon such as
a pool or spa heater that uses chemically treated
water . (This appliance is suitable for lling large or
whirlpool spa tubs with potable water.)
 Do not use substute parts that are not authorized
for this appliance.

 The installaon must conform with local codes or,
in the absence of local codes, with the Naonal
Fuel Gas Code, ANSI Z223.1/NFPA 54, or the
Natural Gas and Propane Installaon Code, CSA
B149.1. If installed in a manufactured home, the
installaon must conform with the Manufactured
Home Construcon and Safety Standard, Title 24
CFR, Part 3280 and/or CAN/SCA Z240 MH Series,
Mobile Homes.
 The appliance, when installed, must be electrically
grounded in accordance with local codes or, in the
absence of local codes, with the Naonal Electrical
Code, ANSI/NFPA 70, or the Canadian Electrical
Code, CSA C22.1.
 The appliance and its appliance main gas valve
must be disconnected from the gas supply piping
system during any pressure tesng of that system
at test pressures in excess of 1/2 psi (3.5 kPa)
(13.84 in W.C.).

 For installaon in residenal and commercial
applicaons.
 Cered for installaon in manufactured (mobile)
homes.

KB Series Manual 5

Parts included
Tools needed
Materials needed
 The appliance must be isolated from the gas supply
piping system by closing its individual manual
shuto valve during any pressure tesng of the gas
supply piping system at test pressures equal to or
less than 1/2 psi (3.5 kPa) (13.84 in W.C.).
 You must follow the installaon instrucons and
those in Care and Maintenance for adequate
combuson air intake and exhaust.

 If a water heater is installed in a closed water
supply system, such as one having a backow
preventer in the cold water supply line, means
shall be provided to control thermal expansion.
Contact the water supplier or local plumbing
inspector on how to control thermal expansion.
 Should overheang occur or the gas supply fail to
shut o, turn o the manual gas control valve to
the appliance.
 Keep the air intake locaon free of chemicals such
as chlorine or bleach that produce fumes. These
fumes can damage components and reduce the life
of your appliance.
 Tankless water heater
 Color coded cold (blue) and hot (red) isolaon
valves
 Pressure relief valve
 MC-91-2 temperature controller (integrated into
indoor models; provided with outdoor models)
 Pipe wrenches (2)
 Adjustable pliers
 Screwdrivers (2)
 Wire cuers
 Gloves
 Safety glasses
 Level
Tools that might be needed
 Hammer drill with
concrete bits
 Saw
 Threading machine with
heads and oiler
 Core drill with diamond
head
 Torch set
 Copper tubing cuer
 Steel pipe cuer
Materials that may be needed
 Soap soluon
 Approved venng
 Teon tape
(recommended) or pipe
compound
 Heat tape
 Pipe insulaon
 Electrical wire and
conduit per local code
 Concrete wall anchors
 Oponal pipe cover
 Oponal temperature
controller
 5/8” ID PVC exible
tubing
 2 conductor 22 AWG
wire for controller
 Single gang electrical
box
 Wire nuts
 Unions and drain valves

6KB Series Manual
Consideraon of care for your water heater should
include evaluaon of water quality.





Total Hardness Up to 200 mg / L
Aluminum * Up to 0.2 mg / L
Chlorides * Up to 250 mg / L
Copper * Up to 1.0 mg / L
Iron * Up to 0.3 mg / L
Manganese * Up to 0.05 mg / L
pH * 6.5 to 8.5
TDS (Total Dissolved Solids) * Up to 500 mg / L
Zinc * Up to 5 mg / L

Environment
Air surrounding the water heater, venng, and vent
terminaon(s) is used for combuson and must be
free of any compounds that cause corrosion of
internal components. These include corrosive
compounds that are found in aerosol sprays,
detergents, bleaches, cleaning solvents, oil based
paints/ varnishes, and refrigerants. The air in beauty
shops, dry cleaning stores, photo processing labs, and
storage areas for pool supplies oen contains these
compounds. Therefore it is recommended that
outdoor models be used for these locaons where
possible.
The water heater, venng, and vent terminaon(s)
should not be installed in any areas where the air may
contain these corrosive compounds. If it is necessary
for a water heater to be located in areas which may
contain corrosive compounds, the following
instrucons are strongly recommended.

Indoor/Internal Water Heaters
 DO NOT Install in areas where air for combuson
can be contaminated with chemicals.
 Before installaon, consider where air has the
ability to travel within the building to the water
heater.
 Where possible, install the water heater in a
sealed closet so that it is protected from the
potenal of contaminated indoor air.
 Chemicals that are corrosive in nature should not
be stored or used near the water heater.
Outdoor/External Water Heaters and Vent
Terminaons of Indoor/Internal Water Heaters
 Install the water heater as far away as possible
from exhaust vent hoods.
 Install as far away as possible from air inlet
vents. Corrosive fumes may be released through
these vents when air is not being brought in
through them.
 Chemicals that are corrosive in nature should not
be stored or used near the water heater or vent
terminaon.
Damage and repair due to corrosive compounds in
the air is not covered by warranty.
Water Quality
* Source: Part 143 Naonal Secondary Drinking Water
Regulaons
If you install this water heater in an area that is
known to have hard water or that causes scale build-
up the water must be treated and/or the heat
exchanger ushed regularly.
When scale build-up in the heat exchanger begins to
aect the performance of the water heater, a
diagnosc code “LC#” will display. Flush the heat
exchanger to prevent damage to it. Scale build up is
caused by hard water set at a high temperature.
Rinnai oers Southeastern Filtraon’s Scale Cuer
Water Condioning System” that oers superior lime
scale prevenon and corrosion control by feeding a
blend of control compounds into the cold water
supply.
You must ensure that clearances will be met and that
the vent length will be within required limits.
Consider the installaon environment, water quality,
and need for freeze protecon. Requirements for the
gas line, water lines, electrical connecon, and
condensate disposal can be found in their respecve
installaon secons of this manual.
Part Number Descripon
103000038 Southeastern Filtratrion
ScaleCuer System 3/4” Feed
103000039 ScaleCuer Rell

KB Series Manual 7
Direct Vent Terminal Clearances (Indoor Units)
[1] A vent shall not terminate directly above a sidewalk or paved driveway
that is located between two single family dwellings and serves both
dwellings.
[2] Permied only if veranda, porch, deck, or balcony is fully open on a
minimum of two sides beneath the oor.
 For clearances not specied in ANSI Z223.1/NFPA 54, clearances are in
accordance with local installaon codes and the requirements of the gas
supplier.
Clearance to opposite wall is 24 inches (60 cm).
For indoor models, you must install a vent terminaon to bring in combuson air and expel exhaust.
   
AClearance above grade, veranda, porch, deck, or balcony 12 inches (30 cm) 12 inches (30 cm)
BClearance to window or door that may be opened 36 inches (91 cm) 12 inches (30 cm)
CClearance to permanently closed window **
D
Vercal clearance to venlated sot, located above the
terminal within a horizontal distance of 2 feet (61 cm) from the
center line of the terminal
**
EClearance to unvenlated sot **
FClearance to outside corner **
GClearance to inside corner **
HClearance to each side of center line extended above meter/
regulator assembly
3 feet (91 cm) within a height 15 feet
(4.5 m) above the meter/regulator
assembly
*
IClearance to service regulator vent outlet 36 inches (91 cm) *
JClearance to nonmechanical air supply inlet to building or the
combuson air inlet to any other appliance 36 inches (91 cm) 12 inches (30 cm)
KClearance to a mechanical air supply inlet 6 feet (1.83 m) 3 feet (91 cm) above if within 10
feet (3 m) horizontally
LClearance above paved sidewalk or paved driveway located on
public property 7 feet (2.13 m) *
MClearance under veranda, porch, deck, or balcony 12 inches (30 cm)  *
INSIDE
CORNERDETAIL
FIXED
CLOSED
OPERABLE
FIXED
CLOSED
OPERABLE
B
B
B
A
J
BM
C
F
B
B
E
D
L
G
A
H
K
I
X
V
AIR SUPPLY INLET
VENT TERMINAL
AREA WHERE TERMINAL
IS NOT PERMITTTED
SNOW
TERMINATION
Clearance in
Ref. A also
applies to
anticipated
snow line

8KB Series Manual
Other Than Direct Vent Terminal Clearances (Outdoor Units)
INSIDE
CORNERDETAIL
FIXED
CLOSED
OPERABLE
FIXED
CLOSED
OPERABLE
B
B
B
A
J
BM
C
F
B
B
E
D
L
G
A
H
K
I
[1] A vent shall not terminate directly above a sidewalk or paved driveway
that is located between two single family dwellings and serves both
dwellings.
[2] Permied only if veranda, porch, deck, or balcony is fully open on a
minimum of two sides beneath the oor.
 For clearances not specied in ANSI Z223.1/NFPA 54, clearances are in
accordance with local installaon codes and the requirements of the gas
supplier.
Clearance to opposite wall is 24 inches (60 cm).
X
V
AIR SUPPLY INLET
VENT TERMINAL
AREA WHERE TERMINAL
IS NOT PERMITTTED
   
AClearance above grade, veranda, porch, deck, or balcony 12 inches (30 cm) 12 inches (30 cm)
BClearance to window or door that may be opened
6 in (15 cm) for appliances ≤ 10,000 Btuh (3
kW), 12 in (30 cm) for appliances > 10,000
Btuh (3 kW) and ≤ 100,000 Btuh (30 kW), 36 in
(91 cm) for appliances >100,000 Btuh (30 kW)
4  (1.2 m) below or to side of opening;
1  (300 mm) above opening
CClearance to permanently closed window **
DVercal clearance to venlated sot, located above the terminal within a
horizontal distance of 2 feet (61 cm) from the center line of the terminal **
EClearance to unvenlated sot **
FClearance to outside corner **
GClearance to inside corner **
HClearance to each side of center line extended above meter/regulator
assembly
3 feet (91 cm) within a height 15 feet (4.5 m)
above the meter/regulator assembly *
IClearance to service regulator vent outlet 36 inches (91 cm) *
JClearance to nonmechanical air supply inlet to building or the combuson
air inlet to any other appliance
6 in (15 cm) for appliances ≤ 10,000 Btuh (3
kW), 12 in (30 cm) for appliances > 10,000
Btuh (3 kW) and ≤ 100,000 Btuh (30 kW), 36 in
(91 cm) for appliances >100,000 Btuh (30 kW)
4  (1.2 m) below or to side of opening;
1  (300 mm) above opening
KClearance to a mechanical air supply inlet 6 feet (1.83 m) 3 feet (91 cm) above if within 10 feet (3
m) horizontally
LClearance above paved sidewalk or paved driveway located on public 7 feet (2.13 m) *
MClearance under veranda, porch, deck, or balcony 12 inches (30 cm)  *

KB Series Manual 9
Addional clearances
Check on whether local codes supersede these
clearances.
 Avoid terminaon locaons near a dryer vent.
 Avoid terminaon locaons near commercial
cooking exhaust.
 You must install a vent terminaon at least 12
inches from the ground.
(0.30 m) between
terminals at same
level
(1.52 m)
vercally
between
terminals
2"
12"
60"
36"
60"
V
V
(1.52 m)
between
terminals at
dierent levels
24"
V
(0.61 m) to wall or parapet
12"
V V
V
60"
V
RU80e, RU98e
RU80i, RU98i
12"
12"
36"
INSIDE
CORNER
V V
(0.30 m) between
terminals at same
level
(0.30 m ) to
an inside
corner
(0.91 m) to venlated
or unvenlated sot
or eve vent; or to a
deck or porch
(1.52 m) vercally
between terminals
(50 mm) between
terminals at same level
(0.30 m) to an
inside corner
The vent for this appliance shall not terminate
 Over public walkways; or
 Near sot vents or crawl space vents or other
area where condensate or vapor could create a
nuisance or hazard or cause property damage; or
 Where condensate or vapor could cause damage
or could be detrimental to the operaon of
regulators, relief valves, or other equipment.
for locang vent
terminaon under a sot (venlated or unvenlated
or eave vent; or to a deck or porch)
 Do not install vent terminaon under a sot vent
such that exhaust can enter the sot vent
 Install vent terminaon such that exhaust and rising moisture
will not collect under eaves. Discoloraon to the exterior of
the building could occur if installed too close.
 Do not install the vent terminaon too close under the sot
where it could present recirculaon of exhaust gases back
into the combuson air intake part of the terminaon.

10 KB Series Manual
Unit clearances





-


 6 * (152) 2 *(51)
 0 (zero) 0 (zero)
 6 (152) 6 (152)
 2 (51) 1/2 (13)
 12 (305) 12 (305)
 0 (zero) 0 (zero)
* 0 inches from vent components and condensate drain
line.
The clearance for servicing is 24 inches in front of the
water heater.
For closet installaon, clearance is 6 inches (152 mm from
the front.





-


 12 (305) 2 (51)
 0 (zero) 0 (zero)
 24 (610) 0 (zero)
 24 (610) 24 (610)
 6 (152) 1/8 (3.2)
 12 (305) 2 (51)
The clearance for servicing is 24 inches in front of the
water heater.
to side
to front
to top
to floor/ground
Freeze Protecon
Make sure that in case of freezing weather that the
water heater and its water lines are protected to
prevent freezing. Damage due to freezing is not
covered by the warranty.
Loss of freeze protecon may result in water damage
from a burst heat exchanger or water lines.
With electrical power supplied, the water heater will
not freeze when the outside air temperature is as cold
as –22°F (-30°C) for indoor models or is as cold as –4°F
(-20°C) for outdoor models, when protected from
direct wind exposure. Because of the “wind-chill”
eect, any wind or circulaon of the air on the unit
will reduce its ability to freeze protect.
The unit may be drained manually. However, it is
highly recommended that:
 drain down solenoid valves are installed that will
automacally drain the unit if power is lost.
These are available in a kit, 104000059. (The
condensate trap drain plug and water drain plug
are not aected by the auto drain down solenoid
valves and will have to be manually opened.)
 a surge protector with terminals is installed which
allows the solenoid valves to operate if the unit is
disabled due to a diagnosc code. This is
available as 104000057.
In addion, the solenoid valves should be connected
electrically to a surge protector with terminals. This
allows the solenoid valves to operate if the water
heater is disabled due to a diagnosc code.
The freeze protecon features will not prevent the
external piping from freezing. It is recommended that
hot and cold water pipes are insulated. Pipe cover
enclosures may be packed with insulaon for added
freeze protecon.
It is recommended that the condensate trap drain line
be insulated. A frozen condensate trap drain line
results in diagnosc code 25.
In the event of a power failure at temperatures below
freezing the water heater should be drained of all
water to prevent freezing damage. In addion, drain
the condensate trap and drain line.

KB Series Manual 11
Maximum vent length

1.Determine the number of 90 degree elbows in the
vent system. (Two 45 degree elbows count as
one 90 degree elbow.)
2.Refer to the table to nd the maximum vent length
based on the number of elbows.
3.Adjust switch No. 1 in the SW1 DIP switch (tan
switches) if required by the applicable note.
 If the length is greater than 21  (6.4 m) then
move switch No. 1 (SW1) to OFF.
 If the length is greater than 15  (4.6 m) then
move switch No. 1 (SW1) to OFF.
 If the length is greater than 9  (2.7 m) then move
switch No. 1 (SW1) to OFF.
Move switch No. 1 (SW1) to OFF.
If you have a longer vent length (see above), switch
No. 1 is required to be in the OFF posion. This
ensures the water heater will run properly. Blocked
ue diagnosc codes and shutdowns may result if
switch No. 1 is not in the correct posion.


(Intake is the short UV protected 90° elbow)









If length is greater
041  (12.50 m) 18  (5.49 m) move
switch #1 to OFF
126  (7.93 m) 3  (0.91 m) move
switch #1 to OFF
211  (3.35 m) move switch #1 to
OFF for any length









If length is greater
041  (12.50 m) 21  (6.40 m) move
switch #1 to OFF
135  (10.67 m) 15  (4.57 m) move
switch #1 to OFF
229  (8.84 m) 9  (2.74 m) move
switch #1 to OFF
323  (7.01m) 3  (0.91 m) move
switch #1 to OFF
417  (5.18 m)
move switch #1 to
OFF for any length
511  (3.35 m)
65  (1.52 m)

(Intake is the long UV protected 90° elbow)

InnoFlue Vent System (single wall SW, 3 inch diameter)


(90° elbow is equivalent to 6 feet; 45° elbow is equivalent to 3 feet.)




041 (12.5)1
135 (10.7)2
229 (8.8)3
323 (7.0)4
417 (5.2)4
511 (3.4)4
65 (1.5)4


(90° elbow is equivalent to 6 feet; 45° elbow is equivalent to 3 feet.)




065 (19.8)1
159 (18.0)2
253 (16.2)3
347 (14.3)4
441 (12.5)4
535 (10.7)4
629 (08.8)4
Example: If you have one elbow then your
maximum vent length is 35 feet (10.7 m).
If your actual length is greater than 15 
(4.6 m) then move switch no. 1 (SW1) to
OFF.

12 KB Series Manual

wall installaon
brackets
1. Idenfy the installaon locaon and conrm that
the installaon will meet all required clearances.
2. Securely aach the water heater to the wall
using any of the holes in the wall installaon
brackets which are at the top and boom of the
water heater. Ensure that the aachment
strength is sucient to support the weight.
Refer to the weight of the water heater in the
Specicaons secon.
Use a leveling tool to ensure that the water
heater is level. Proper operaon requires that
the water heater be level.
NOTE: The water heater should be installed in an
upright posion. Do not install upside down or on its
side.


□The water heater is not exposed to corrosive
compounds in the air.
□The water heater locaon complies with the
clearances.
□For indoor models, the planned venng will not
exceed the maximum length for the number of
elbows used.
□The planned venng terminaon/air intake
locaon meets the clearances.
□The water supply does not contain chemicals or
exceed total hardness that will damage the heat
exchanger.
□A standard 3 prong 120 VAC, 60 Hz properly
grounded wall outlet (for indoor models) or other
120 VAC, 60 Hz source is available.
□The installaon must conform with local codes or,
in the absence of local codes, with the Naonal
Fuel Gas Code, ANSI Z223.1/NFPA 54, or the
Natural Gas and Propane Installaon Code, CSA
B149.1. If installed in a manufactured home, the
installaon must conform with the Manufactured
Home Construcon and Safety Standard, Title 24
CFR, Part 3280 and/or CAN/SCA Z240 MH Series,
Mobile Homes.
□


 
Slide the plasc trim pieces on each side of the water
heater to expose the screws.
Remove the 4 screws and pull o the front panel.

KB Series Manual 13

Install the correct venng for your model according to the venng manufacturer’s instrucons and the
guidelines below. Refer to the manufacturer’s technical literature for specic part numbers and instrucons.
 
   
Ubbink Rolux Condensing
Vent System 800-621-9419 678-829-1666 www.rinnai.us
Ubbink Concentric to Twin
Pipe Adaptor 800-621-9419 678-829-1666 www.rinnai.us
Centrotherm InnoFlue Vent System (single
wall SW, 3 inch diameter) 877-434-3432 518-618-3166 [email protected]om www.centrotherm.us.com
Heat-Fab Saf-T Vent SC system 800-772-0739 413-863-4803 [e-mail],
www.heaab.com
Metal-Fab Corr/Guard Vent/Air Intake
System 800-835-2830 316-943-2717 [email protected]m, www.metal-fabinc.com
Ipex Concentric Kit / Low Prole
Terminaon Kit
U.S. - 800-463-9572
CA. - 866-473-9462 —www.ipexamerica.com www.ipexinc.com
—
PVC schedule 40
PVC-DWV
CPVC schedule 40
(with Ubbink Concentric to
Twin Pipe Adaptor)
———
   
Ubbink Rolux 184162PP 223176PP, 223177PP
Centrotherm InnoFlue ICRT3539 ISELL0387UV
Heat-Fab Saf-T Vent Saf-T Vent CI Plus Wall
Terminaon Saf-T Vent CI Plus Rain Cap
Metal-Fab Corr/Guard 3CGRVDK 3CGRVT
Ipex Concentric Kit 3”- 196006 /197009
4”-196021 /197021
3”- 196006 /197009
4”-196021 /197021
Ipex Low Prole Terminaon Kit —3”- 196985
4”- 196986
—
PVC schedule 40
PVC-DWV
CPVC schedule 40
(with Ubbink Concentric to
Twin Pipe Adaptor)
Reference “Approved PVC/
CPVC Vent Conguraons”
Table
Reference “Approved PVC/
CPVC Vent Conguraons”
Table

14 KB Series Manual
Venng Guidelines

 Do not use cellular core PVC/CPVC, Radel, ABS, or
galvanized material to vent this appliance.
 Do not combine vent components from dierent
manufacturers.
 Vent diameter must not be reduced.
 Do not connect the venng system with an
exisng vent or chimney.
 Do not common vent with the vent pipe of any
other manufacturer’s water heater or appliance.
Rinnai water heaters can only be common vented
using a Rinnai cered common vent system.

 This water heater is a direct vent water heater and
therefore is cered and listed with the vent
system. You must use vent components that are
cered and listed with the water heater model.
 The vent system must vent directly to the outside
of the building and use outside air for combuson.
 Avoid dips or sags in horizontal vent runs by
installing supports per the vent manufacturer’s
instrucons.
 Support horizontal vent runs every four feet and
all vercal vent runs every six feet or in
accordance with local codes.
 Venng should be as direct as possible with a
minimum number of pipe ngs.
 Vent connecons must be rmly pressed together
so that the gaskets form an air ght seal.
 The vent piece connected to the water heater
must be secured with one self-tapping screw.

 Refer to the instrucons of the vent system
manufacturer for component assembly
instrucons.
 If the vent system is to be enclosed, it is suggested
that the design of the enclosure shall permit
inspecon of the vent system. The design of such
enclosure shall be deemed acceptable by the
installer or the local inspector.

If it becomes necessary to access an enclosed vent
system for service or repairs, Rinnai is not responsible
for any costs or dicules in accessing the vent
system. The warranty does not cover obtaining
access to a vent system in an enclosed environment.

KB Series Manual 15
Flue Installaon with Concentric Venng (indoor models only)
Install the venng terminaon according to the diagrams and instrucons below.
Secure the first vent component to the water heater
with one self-tapping screw at the hole.

Securing Screw

Slope the venting toward the appliance according to
the vent manufacturers installation instructions.
Dispose of condensate per local codes.
Slope the venting toward the appliance according to
the vent manufacturers installation instructions.
Dispose of condensate per local codes.

16 KB Series Manual
 Comply with the exhaust clearances found in the Rinnai Operaon and Installaon Manual.
 Only one appliance can be aached to the vent system.
 Install the system in according to the Centrotherm installaon instrucons.
 Use the 3”/5” concentric to twin pipe adaptor and 3” diameter venng.
 The vent terminaon and air intake must be in the same pressure zone.
 Do not exceed maximum straight vent length with number of elbows as shown in the tables on the next
page.
 Maintain the clearances shown in the gures below.
 cellular core PVC, CPVC, Radel, ABS or Galvanized ducts as venng
materials.


11”
5”
Intake
Oponal
Vent
Flue Installaon with Centrotherm Venng (indoor models only)
Install the venng terminaon according to the diagrams and instrucons below.

KB Series Manual 17
The newly cered vent system is comprised of a Concentric to Twin Pipe Adaptor (adaptable to 3 and 4 inch sizes),
PVC/CPVC pipes, ngs and either the IPEX System Concentric Vent Kit Assembly (System 636), snorkel terminaon or tee
terminaon.
Rinnai has cered the Ubbink 3”/5” to 3”/3” Concentric to Twin Pipe Adaptor and other venng equipment to be used
with the oponal PVC/CPVC twin pipe venng system for use with the following condensing water heater models only:
----
Installaons must comply with local requirements and with the Naonal Fuel Gas Code, ANSI Z223.1/NFPA 54 for U.S.
installaons or CSA B149.1 for Canadian installaons.  use cellular core PVC, CPVC, or Radel based pipe materials
for the exhaust vent. Vents  be of solid core pipes ONLY.

Use only the materials listed in this secon for vent, air intake pipe and ngs (See vent and air piping materials table).
Failure to comply with this warning could result in severe personal injury, death or substanal property damage.

The Ubbink Concentric to Twin Pipe Adaptor (above) is ULC S636 approved and is listed by the applicable agencies having
jurisdicon and is cered for use throughout the U.S. and Canada. The Concentric to Twin Pipe Adaptor is supplied
exclusively through Rinnai and/or its distributors.

PVC venng cannot be used if the condensing water heater, under the following condions:
 The water heater is installed in a recirculaon system and the thermostat seng is greater than 150 F (65.5 C).
 The water heater is used in a combinaon domesc water and space heang applicaon which requires a thermostat
seng greater than 150 F (65.5 C).

Twin Pipe PVC/CPVC Vent Installaon
Ubbink® Concentric to Twin Pipe Adaptor
Exhaust
Combuson
Air Inlet

18 KB Series Manual
Tankless Water Heaters must be vented and furnished with intake air and exhaust vent using piping and
methods described in this secon. Each water heater must have its own intake and vent. DO NOT common vent
with any other appliance using this method. Inspect nished vent and intake air piping thoroughly to ensure all
are airght and comply with the instrucons provided and with all requirements of applicable codes. Failure to
provide a properly installed vent and air system will cause severe personal injury or death.

-The combuson air intake terminaon ng must be installed with the clearances and
geometry relave to the exhaust (vent) depicted in this secon to ensure that ue products do not enter the
combuson air intake. Ensure that the intake air will not contain any of the contaminants as outlined in the
“” secon. Contaminated intake air will damage the water heater, resulng in
possible severe personal injury, death, or substanal property damage.
 - The exhaust (vent) terminaon ng must be installed with the clearances and geometry relave to
the combuson air pipe as depicted in this secon to ensure that ue products do not enter the combuson air
intake

If the vent and/or combuson air intake piping conguraons covered in this manual cannot be applied to a
specic installaon, contact Rinnai’s Applicaon Engineer group for assistance. Other conguraons may be
available.

Installaons must comply with local requirements and with the Naonal Fuel Gas Code, ANSI Z223.1/NFPA 54
for U.S. installaons or CSA B149.1 for Canadian installaons.  use cellular core PVC, CPVC, or Radel
based pipe materials for the exhaust vent. Vents  be of solid core pipes ONLY.

Use only the materials listed in this manual for vent, combuson air intake pipe and ngs (See “Vent and Air
Piping” table) . Failure to comply with this warning could result in severe personal injury, death or substanal
property damage.

If used, a masonry chimney can  be used as a for the exhaust and combuson air intake pipes.
The exhaust and air piping must be installed as instructed in this manual. The chimney must be used only for
Rinnai Water Heater(s) vent chase. appliance or replace can be connected to the chimney. Exhaust
and air piping materials must comply with this instrucon. The chimney must be ed with a sealed access
opening to facilitate interior inspecon. The chimney chase (and liner, if installed) to be inspected annually for
any degradaon. Failure to comply could result in severe personal injury, death, or substanal property damage.


KB Series Manual 19
 All PVC/CPVC IPEX Concentric Vent Kit (CVK)
Assemblies are cered to ULC S636. Where ULC S636
compliance is required, use only System 636 pipe,
ngs and cement at terminal connecon.
 use PVC/CPVC on Non-Condensing Units.
 operate unit unl venng is completely
installed and all solvents and glues have bonded.
 All PVC/CPVC exhaust vent material used in
Canada must be S636 cered.
 If the preferred venng opon is a twin pipe PVC/CPVC
conguraon, the Rinnai approved twin pipe adaptor
must be used.
For further details on listed PVC/CPVC venng
material (table below) refer to the installaon manual of
the PVC/CPVC manufacturer.
Twin Pipe PVC/CPVC Vent Installaon Requirments:

  
 

Vent or combuson air
intake pipe & Fings
PVC schedule 40 ANSI/ASTM D1785 Thermoplasc vent pipe must be
cered to ULC S636.
Intake pipe may be of any material listed
(le).
PVC-DWV ANSI/ASTM D2665
CPVC schedule 40 ANSI/ASTM F441
PVC pipe cement &
primer
PVC ANSI/ASTM D2564
CPVC ANSI/ASTM F493

Terminaon Vent
Screens Polyethylene 3" Vent screen: IPEX part # 196051; 4" Vent screen: part #: 196052 (Screens are fricon ed inside terminaon ng bells.)
The listed vent, vent ngs, terminaon, cleaner and glue are all cered as part of the condensing tankless
water heater vent system.


Failure to correctly install vent and combuson air intake pipes of the water heater to atmosphere as outlined
in this venng secon will result in death from asphyxiaon (from carbon monoxide), re or explosion. 
operate the water heater without proper venng (vent and combuson air intake). Always inspect the vent
terminal unit, combuson air intake pipe, and the enre vent system axed to the water heater for proper
installaon at equipment commissioning and at least annually thereaer.

 Locate the vent outlet where ue gases will not harm
surrounding plants and/or cooling equipment.
 Avoid locang vent where prevailing winds could
aect the performance of the water heater or cause
recirculaon of the ue gases.
 terminate the venng over a public walkway
or over an area where condensate or vapor can cre-
ate a nuisance / hazard or where condensate can be
detrimental to the operaon of equipment such as
regulators or relief valves
 Water Heater ue gases must be piped from the
appliance to the outside, Installer MUST adhere to the
instrucons provided herein and the most
recent Water Heater Manual and all applicable codes.
 Exhaust and combuson air must terminate through
the same sidewall or roof as the terminaons must be
in the same pressure zone and face same direcon.
 Vent pipe must terminate either through the sidewall
or through the roof, exhaust/vent terminaon and/or
intake air openings shall adhere to clearances as set
forth in the Direct Vent Terminaon Clearances
diagram.
 Each Condensing Tankless Water Heater requires a
separate vent system.
 If common venng is required, refer to Rinnai
Common Vent Installaon Manual (latest revision) for
instrucons on oponal venng method as well as to
verify which tankless models may be common vented.
 Use only PVC/CPVC 3” and 4” Venng.

20 KB Series Manual
For PVC/CPVC vent systems reduce the maximum
allowable length for each elbow and terminaon type as
follows :


 For PVC/CPVC vent systems reduce the maximum
allowable length for each elbow and terminaon type
as follows:
 Vent and combuson air intake pipe diameters to be as
specied in maximum equivalent vent length tables of
this document.
 Do not exceed vent and combuson air intake pipe
MAXIMUM lengths (Lengths are specic to models and
fuel type).
 2.5 feet for every 45° elbow.
 5 feet for every 90° elbow.
 Terminaon (refer Approved Vent Component
table of this secon)

There are two opons for determining the vent lengths/
components necessary for the installaon.
The installer can use the vent length calculaon
sheet (below), lling in the quanty of the vent components
in order to calculate the total equivalent vent lengths.
The installer can use the maximum vent lengths
tables on the next pages to determine the amount of
straight pipe that can be used with a specic terminaon
type and quanty of elbows.
Determining Total System Equivalent Length
(A blank copy of the Equivalent Vent Length Calculaon Sheet is located at the end of this secon)
Ensure switch #1 in the bank of eight tan dip switches is in OFF posion if vent length is greater than 21 (6.4m).

Choose the vent type and ll out the calculaon sheet
below. When determining equivalent combuson air and
vent length, add 5 feet for each 90° elbow, 2.5 feet for each
45° elbow.

 (assume 3” diameter pipes for
natural gas unit):
 Twin pipe (parallel) with snorkel terminal
 Combuson air pipe length: 40  straight pipe with 3 x
90° elbows
 Exhaust pipe length: 40  straight pipe with 3 x 90°
elbows 
 Snorkel Terminaon: 10 equivalent feet (reference
Approved PVC/CPVC Terminaon Components table)

 Equivalent Combuson air pipe length: [40+(3 X 5)+10]
= 65 
 Equivalent Vent Length: [40+(3 X 5)+10] = 65 
 Total = 65 . for both exhaust and combuson air
pipes, which is the maximum allowable vent length for
3” PVC/CPVC on a natural gas unit. If longer lengths
are required, go to the 4” diameter pipe conguraon
which is cered for up to 100 equivalent feet.
Maximum equivalent vent lengths are specic to the fuel
type of the water heater. It is imperave when performing
vent calculaons, the following be taken in consideraon:









1) 90 elbow 3515
2) 45 elbow 2.5 0
3) IPEX Low Prole Terminaon 50
4) IPEX 4" Concentric Terminaon 20 0
5) IPEX 3" Concentric Terminaon 20 0
6) 3" Tee Terminaon 50
7) 4" Tee Terminaon 50
8) 3" Snorkel Terminaon 110 10
9) 4" Snorkel Terminaon 10 0
10) Length of Straight Secon in feet NA 40 40
 (add up
lines 1 through
65